There have recently been image forming systems in which an image forming device is coupled with a peripheral unit which is suitable for environment or requirements of the user.
As an example of such image forming systems, there is an image forming system in which an image forming device is coupled with a switchback machine as a peripheral unit. The image forming system operates in the following manner: first, the image forming device discharges a recording material (sheet), an image having been formed on one of two sides of the sheet, to the switchback machine. Then after being reversed by the switchback machine, the sheet is supplied to the image forming device. Since images can be formed on both sides of a sheet, the image forming system can realize resource saving.
As another example, there is an image forming system in which an image forming device is coupled with a post-treatment device as a peripheral unit. This image forming system operates in the following manner: a sheet on which an image has been formed by the image forming device is sent to the post-treatment device. Then in the post-treatment device, the sheet is subjected to processes such as punch hole forming, stapling, and sorting. This image forming system makes it possible to improve the operating efficiency.
In this manner, in image forming systems in which an image forming device is coupled with a peripheral unit, not only the type of the peripheral unit but also the type of the image forming device can be arbitrarily determined in accordance with the intended use such as copying and printing. Thus, since it is possible to arbitrarily select and combine an image forming device and a peripheral unit, the final state of an image can be arbitrarily selected or arranged by the user, and hence these image forming systems excel in extensibility.
Incidentally, in the above-mentioned image forming systems, a sheet may jam in a sheet carrying system of the image forming device or the peripheral unit. When this occurs, the user has to perform operations to recover the image forming system, such as removing the jammed sheet.
In this case, when, in order to perform the unjamming treatment, a space between the image forming device and the peripheral unit has to be made by, for instance, pulling a predetermined unit of the image forming device towards the peripheral unit, it is necessary to carry out a lot of operations such as removing or repositioning the peripheral unit coupled with the image forming device, before performing the unjamming treatment. Further, since these operations require spaces for the operation to remove the peripheral unit and for temporarily placing the removed peripheral unit, it is often required to make these spaces by laboriously removing objects occupying the spaces.
Japanese Laid-Open Patent Application No. 4-86836/1992 (Tokukaihei 4-86836; published on Mar. 19, 1992) discloses an image forming device arranged such that the foreside of the main body of the image forming device has an opening, and inside the opening, an openable unit with members such as a carrying member is provided. In this image forming device, the user can put his/her hand into the opening and remove the jammed sheet. Since the unjamming treatment can be performed through the opening without making a space between the image forming device and the peripheral unit, it is unnecessary to remove or reposition the peripheral unit to treat the paper jam, even if the peripheral unit remains to be coupled with the image forming device.
Also, Japanese Laid-Open Patent Application No. 6-286922/1994 (Tokukaihei 6-286922; published on Oct. 11, 1994) discloses an image forming system in which a peripheral unit coupled with an image forming device is composed of a plurality of subunits. In this image forming system, the subunits can be moved on a support on the floor so as to be away from the image forming device, and hence spaces to which the subunits are moved are provided in advance. When paper jam occurs around the connection between the image forming device and the subunit or inside the subunit, the user uncouples a corresponding subunit from the image forming system and moves the subunit on the support, so as to make a space around the point of the jam. Then using this space, the user removes the jammed sheet. In this image forming system, a space for performing the unjamming treatment, which is made by uncoupling the image forming device and the peripheral unit, is provided on the support in advance.
However, according to the image forming device of Japanese Laid-Open Patent Application No. 4-86836/1992, since the space for removing the jammed sheet is made inside the image forming device, the space to be made is not sufficiently large so that the removal of the sheet is still difficult. Moreover, this space is noncontributory to remove the paper jam inside the peripheral unit.
Even if the invention of Japanese Laid-Open Patent Application No. 6-286922/1994 is incorporated into the foregoing invention in order to perform the unjamming treatment by uncoupling the image forming device and the peripheral unit and making a space sufficient for the treatment, when it is arranged so that a part of the image forming system is pulled off for performing the unjamming treatment, it is still necessary for the user to detach and move a corresponding subunit of the peripheral unit before pulling off the part of the image forming system, and hence laborious operations are still required.
Further, even if the space on the support, to which the peripheral unit is to be moved, is provided in advance, since the space is provided beside the image forming system, goods are often placed on the support on the floor and a part of another device easily enters the space. Thus, the space to which the peripheral unit is to be moved cannot always readily function. On this account, in some cases, it is still necessary to laboriously remove the obstacles from the space, on the occasion of the paper jam.
In this manner, conventional image forming systems have had such a problem that it is cumbersome to carry out the operation of uncoupling an image forming device and a peripheral unit, on the occasion of performing unjamming treatment between the image forming device and the peripheral unit.